sciencemonster

With these one-wire circuit, especially old crusty ones, you can improve conductivity by running jumpers to ground.

Running a wire from the nut that secures the light to the bracket down to the closest nut on the bike - or even better, back to a nut on the bracket that secures the generator. Basically, you are making a two-wire system instead of depending on the frame to act as a wire. Since you are replacing the one wire anyway, it's simple to replace it with a two conductor wire and be done with it.

Finding contacts on both ends of the circuit as close to the light socket and generator will eliminate any flickering caused by faulty connections.

You could also clean off the contacts on the light sockets - a pencil eraser works wonders. Contact cleaner works even better. All these conductive electrical contact surfaces build up a type of invisible rust that interferes with the circuit, expecially one as haphazard and low amperage as a bicycle light. Use the eraser on the threads of the bulb, too.